Primitive files:
    merged.dta: payments, electors, candidates, and members data merged
    collapsed.dta: merged.dta collapsed to the farmer-year level
    org_ids.dta: a list of farmer IDs that are confirmed organizations

Variables used from primitive files:
    customer_code: farmer ID
    election_year_desc: election year based on description in raw data
    voted: dummy for voting in year
    ran: dummy for running in year
    winner: dummy for winning in year
    served: dummy for serving in year
    amt_all: total program payment amount in year
    amt_prc: total price support program payment amount in year
    amt_con: total conservation program payment amount in year
    amt_*_lag1: total payment amount in previous year
    amt_*_lead1: total payment amount in proceeding year
    any_neg: farmer-level dummy for ever having received negative payments
    hq_state_code: USDA code for state
    hq_county_code: USDA code for county


